Because she´s not used to being loved, she has this self destructive pattern and she thinks that she will mess things up and that she doesn´t deserve him that´s why she gets involved with Cook bcause he´s as careless as she is and she´s not afraid to hurt him. She loves Freddy...
Because she likes to be in control, likes to have all the power. And she knew she might really like Freddie, therefore she rejected him. Because if she'd accepted him. She would have ibingiay him the power to puso her. She never reveals her true self to people because that gives them power. But she begins to see in the end of the third series that doing that has felt her alone.